Chief exec Dan Hesse, speaking at the Competitive Carriers Association trade show in New Orleans, said the new markets include Los Angeles; Charlotte, N.C., and Memphis, Tenn. He also noted that customers are seeing LTE in cities that haven't been officially announced yet, such as New York, San Francisco, and Washington, D.C.
Sprint has been playing catch-up in terms of 4G LTE, lagging far behind rivals Verizon Wireless and AT&T. It earlier made a bet on Clearwire's WiMax network, but later chose to go with LTE after the rest of the market moved in that direction. Under Sprint's Network Vision plan, which is estimated to cost $4 billion to $5 billion, the company is shutting down its iDEN-based Nextel network, moving to 4G LTE, and simultaneously improving its 3G CDMA coverage.
A rollout to Los Angeles and the other new markets has been rumored for a while, and reports last week pegged April 12 as the launch date for those cities. Most of Sprint's early rollouts were in smaller cities.
Meanwhile, Hesse on Thursday said Sprint has reached an LTE roaming agreement with a small Mississippi-based carrier called CSpire.
Here's the full list of Sprint's 21 new markets:
Albemarle, N.C.; Bloomington, Ind.; Charlotte, N.C.; Contra Costa County, Calif.; Denison, Texas; Greeneville, Tenn.; Joplin, Mo.; Kerrville, Texas; Lafayette, Ind.; Lincolnton, N.C.; Los Angeles; Mankato/North Mankato, Minn.; Memphis, Tenn.; Norfolk/Virginia Beach/Newport News, Va.; Palm Bay, Fla.; Port St. Lucie, Fla.; Rochelle, Ill.; Salisbury, N.C.; Shelby, N.C.; Tullahoma, Tenn.; West Palm Beach, Fla.
Sprint has announced more than 170 markets where LTE will be available in the coming months, and on Thursday, it added many more, including Fargo, N.D..; Orlando, Fla.; Portland, Ore.; and Tulsa, Okla.
Currently, Sprint's LTE is available in 88 markets.
Updated at 7:40 a.m. PT with details about the cities in the rollout.